Systematic Reviews

Question 1

What are systematic reviews and their key features ?

Answer 1

A systematic review is a structured and comprehensive synthesis of research studies which aims to answer a specific research question

• induces studies relevant to the question being asked
• minimise bias in findings and conclusions
• vital to well informed decision making in healthcare
• predefined research question and inclusion/exclusion criteria
• critical appraisal and synthesis of findings
• often includes meta analysis

Systematic reviews follow a rigorous methodology, while narrative reviews are more subjective and less structured

Question 2

Describe the process of conducting a systematic review:

Answer 2

Define a clear research question or objective - use the PICO framework for clinical research

Develop a clear protocol outlines methods, inclusion/exclusion criteria, and databases to be searched

Comprehensive literature search - use multiple databases

Conduct rigorous screening of studies - inclusion/ extraction criteria,

Data extraction - extract key study data, assess quality and risk of bias

Synthesise the findings to draw conclusions - meta analysis if appropriate, critical appraisal & interpretation

Question 3

Describe the benefits and limitations of systematic reviews

Answer 3

Benefits:

• comprehensive synthesis of existing evidence
• minimises bias via use of structured methodology
• facilitates evidence-based decision making for policy and practice
• identifies research gaps guiding future studies

Limitations:

• can be time-consuming, expensive and labour intensive to conduct
• quality of review subject to availability and quality of existing studies
• risk of publication bias
• study results can be heterogenous if studies vary significantly in design/outcomes

Question 4

What Are the Components of a Good Systematic Review?

Answer 4

Focused research question - use of PICO

Comprehensive literature search - multiple databases

Rigorous study selection and screening - clear predefined eligibility

Quality assessment - Critical appraisal of the included studies to evaluate quality and
risk of bias

Transparent methodology - detailed and reproducible process for selecting, assessing, and synthesising results (use of PROSPERO)

Balanced and unbiased synthesis - all findings reported, synthesis addresses question discusses study implications

Clear reporting in accordance with reporting guidelines

Question 5

Describe the value of completing a meta analysis:

Answer 5

Combines the findings of each
study

Can compare the effect of each study

Increase the power and precision (by pooling the results)

Test statistical significance

Produce a single ‘average’ value

Allows the conduct of subgroup analysis (e.g. by country, by age)

Can conduct sensitivity analysis (e.g. low risk versus high risk of bias)

Question 6

Describe systematic reviews importance in healthcare:

Answer 6

Provide a comprehensive and unbiased synthesis of existing evidence

Uses:

• informs clinical practice by providing evidence
• policy-makers who make policy decisions about healthcare
• Assessing the effectiveness of treatments, interventions, or diagnostic tests
• Evaluating disease risk factors and epidemiological trends

Question 7

Describe the different types of systematic reviews:

Answer 7

Intervention Review:

• assesses the effectiveness and safety of an intervention
• Focuses on cause-effect relationships between an intervention and an outcome

Prevalence Review:

• estimates the prevalence (how common a condition is) in a specific population
• Includes cross-sectional studies, as they provide prevalence estimates at a single point in time
• cant establish causality

Diagnostic Accuracy Review:

• evaluates how well a diagnostic test correctly identifies individuals with or without a disease
• Focuses on comparing new diagnostic tests against a gold standard

Prognostic Accuracy Review:

• evaluates factors influencing disease progression or patient outcomes
• ## Includes cohort studies to assess how variables affect prognosis over time

Question 8

Describe some real world applications of systematic reviews:

Answer 8

COVID-19 Treatments: Rapid systematic reviews informed global treatment recommendations.
Cancer Screening Guidelines: Meta-analyses of randomized trials shaped screening policies.
Public Health Policies: Systematic reviews on air pollution and health influenced environmental regulations.